diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 84de6acc..e42bf07a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,9 +10,10 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: shivammathur/setup-php@v2
         with:
+          # TODO: Upgrade to PHP 8.5 when VCR releases a version compatible with it
           php-version: '8.3'
       - name: install dependencies
         run: make install
@@ -22,10 +23,10 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        # TODO: Add 8.4 when VCR releases a version compatible with it
+        # TODO: Add 8.4/8.5 when VCR releases a version compatible with it
         phpversion: ['8.1', '8.2', '8.3']
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.phpversion }}
@@ -52,9 +53,10 @@ jobs:
     if: github.ref == 'refs/heads/master'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: shivammathur/setup-php@v2
         with:
+          # TODO: Upgrade to PHP 8.5 when VCR releases a version compatible with it
           php-version: '8.3'
       - name: Install Dependencies
         run: make install
diff --git a/CHANGELOG.md b/CHANGELOG.md
index faa5b493..ec28fb06 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # CHANGELOG
 
-## Next Release
+## v8.4.0 (2025-11-24)
 
 - Adds the following functions:
   - `embeddable.createSession`
diff --git a/composer.json b/composer.json
index cc1b01e8..4178ef05 100644
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
   "name": "easypost/easypost-php",
   "description": "EasyPost Shipping API Client Library for PHP",
-  "version": "8.3.0",
+  "version": "8.4.0",
   "keywords": [
     "shipping",
     "api",
diff --git a/lib/EasyPost/Constant/Constants.php b/lib/EasyPost/Constant/Constants.php
index ae2e8945..123a72f8 100644
--- a/lib/EasyPost/Constant/Constants.php
+++ b/lib/EasyPost/Constant/Constants.php
@@ -11,7 +11,7 @@ abstract class Constants
     const BETA_API_VERSION = 'beta';
 
     // Library constants
-    const LIBRARY_VERSION = '8.3.0';
+    const LIBRARY_VERSION = '8.4.0';
     const SUPPORT_EMAIL = 'support@easypost.com';
 
     // Validation